<template>
<div>
  <h4>ToDoListApp</h4>
  <div class="todo-container">
    <div class="todo-wrap">
      <MyHeader :addTodo="addTodo"/>
      <List :todos="todos" :checkTodo="checkTodo" :deleteTodo="deleteTodo"/>
      <MyFooter :todos="todos" :checkAllTodo="checkAllTodo" :clearAllTodo="clearAllTodo"/>
    </div>
  </div>
</div>
</template>

<script>
import MyHeader from '../components/todolist/MyHeader'
import List from '../components/todolist/List'
import MyFooter from '../components/todolist/MyFooter'
export default {
  name: 'ToDoListApp',
  components: {
    MyHeader, List, MyFooter
  },
  data() {
    return {
      //由于todos是MyHeader组件和MyFooter组件都在使用，所以放在App中（状态提升）
      todos:JSON.parse(localStorage.getItem('todos')) || []
    }
  },
  methods: {
    //添加一个todo
    addTodo(todoObj){
      this.todos.unshift(todoObj)
    },
    //勾选or取消勾选一个todo
    checkTodo(id){
      this.todos.forEach((todo)=>{
        if(todo.id === id) todo.done = !todo.done
      })
    },
    //删除一个todo
    deleteTodo(id){
      this.todos = this.todos.filter( todo => todo.id !== id )
    },
    //全选or取消全选
    checkAllTodo(done){
      this.todos.forEach((todo)=>{
        todo.done = done
      })
    },
    //清除所有已经完成的todo
    clearAllTodo(){
      this.todos = this.todos.filter((todo)=>{
        return !todo.done
      })
    }
  },
  watch: {
    todos:{
      deep:true,
      handler(value){
        localStorage.setItem('todos',JSON.stringify(value))
      }
    }
  },
}
</script>

<!-- Add "scoped" attribute to limit CSS to this component only -->
<style scoped>
/*base*/
body {
  background: #fff;
}
.btn {
  display: inline-block;
  padding: 4px 12px;
  margin-bottom: 0;
  font-size: 14px;
  line-height: 20px;
  text-align: center;
  vertical-align: middle;
  cursor: pointer;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.2), 0 1px 2px rgba(0, 0, 0, 0.05);
  border-radius: 4px;
}
.btn-danger {
  color: #fff;
  background-color: #da4f49;
  border: 1px solid #bd362f;
}
.btn-danger:hover {
  color: #fff;
  background-color: #bd362f;
}
.btn:focus {
  outline: none;
}
.todo-container {
  width: 600px;
  margin: 0 auto;
}
.todo-container .todo-wrap {
  padding: 10px;
  border: 1px solid #ddd;
  border-radius: 5px;
}
</style>
